The field of this invention relates to an apparatus for drying fabrics, in particular clothing, or food stuffs, wherein the drying action is facilitated through the applying of a vacuum.
Clothes drying apparatuses have been known for a substantial period of time. The most common form of a clothes dryer is one which operates by tumbling the clothes in an enclosed drum while raising the temperature sufficiently to cause evaporation of the moisture from the clothes. While this type of dryer apparatus has been satisfactory, when considering the substantial number of such dryers being employed, there is required a substantial energy output to produce the heat that is being used by these dryers, as well as the electrical energy output required to operate the dryer.
Energy conservation is rapidly becoming of the utmost importance. If some type of clothes dryer could be constructed which did not employ the use of heat energy, or used very little, and which used a substantially lesser amount of energy in order to satisfactorily dry the clothes, that type of dryer would be most desirable.
In the past it has been known that applying of a vacuum to the wet clothes will cause substantial removal of the moisture in the clothes. The use of a vacuum for drying clothes is most advantageous. Firstly, the fibers of clothes which are softened by the washing process, are caused to expand in the vacuum and are dryed in the expanded condition which results in a softness and fluffiness not otherwise possible. Secondly, the non-application of heat (or small amount of heat) totally eliminates the possibility of scorching delicate fabrics. Thirdly, since the vacuum reaches into every portion of the clothes, there is no necessity for rapid drum rotation. The dry fibers are therefore not pounded into lint. This creation of lint causes the clothes to wear out more quickly. Fourthly, approximately one half of the moisture is vaporized and removed in the first quarter of drying time. The total drying time is less than one half of that required by conventional heat-applying dryers.
Previous attempts at designing a vacuum dryer apparatus have resulted in a substantially complexly constructed structure. Such a structure is difficult to manufacture, costly to manufacture and requires an increased amount of maintenance than conventional dryers.
A second major application for a vacuum facilitated dryer is the drying of foodstuff material, especially fruit and vegetable rind and pulp. These materials are very suitable for animal feeds and supplements when dried. In the wet state they are too heavy to transport and process and are prone to decay. Present thermal-drying techniques are cost-prohibitive at the low temperatures that would be required to avoid material breakdown.